It reminds me of De Chirico and Pittura Metafisica which was a small art movement in Italy just before WWI.
I think that the backrooms are a kind of reaction to the total corporatization of american life. Just like how Pittura Metafisica was a reaction to the futurists. The futurists were obsessed with machines and going fast, their art was full of movement and metallic forms and so on. De Chirico's was the exact opposite, these ancient Greek statues and buildings standing totally still in a weird autumn light, with meaningful things (statues, grand columns, and so on) placed into meaningless landscapes often with perspective or lighting that was purposefully not correct.
I don't really know too much about De Chirico's rationale for making paintings like this but I suspect it had to do with the industrialization and loss of the old ways of life that he experienced and the rapidly changing social attitude of the time. He took these grand imperial symbols and symbols of modernity and made them feel alienating and unsettling. Of course we know what happened historically as a result of the futurists.
So I think this could be what the backrooms are, a purposeful choice to see this totalizing corporatization of everything as opposite of what it is typically portrayed: it is lifeless, dead, meaningless, non-unique. It's taking a form that is treated a certain way in society (the artifacts of corporate america) and totally inverting it.
Has a lot in common with Vaporwave, I really like it. Not a huge fan of the horror part of it although I guess that's artistically relevant, but moreso this feeling of alienation, sadness, disconnection. It's lurking beneath the surface of our daily life. Think of what working at the Meta campus might look like (bright, cheerful, sunny, aesthetically pleasing) and then think of how the app which is created by that work actually makes people feel (alienated, disconnected, sad, enraged). That's the metaphor, it's the contradiction.